What differences have been observed between prints made with the driver and the plugin?
While there do not appear to be any significant differences in gamut between the driver and the plugin, the plugin nevertheless does show some subtle improvements in image quality:
Smoother gradations in areas of gradual transition in color or tone
A very slightly “sharper” appearance to the naked eye, perhaps due to finer transitions that create higher accutance. If you are printing with files that contain at least 12 bits of real data (16 bit conversion of RAW files from a DSLR) and want the highest image quality, printing through the plugin is recommended.
What differences have been observed between prints made with the driver and the plugin?
While there do not appear to be any significant differences in gamut between the driver and the plugin, the plugin nevertheless does show some subtle improvements in image quality: